1. Field of the Invention
This invention pertains to a bidirectional device which converts a series of data bits partitioned into first groups of frames corresponding to a first type of interface into second groups of frames having a second type of interface. More particularly the device converts groups of frames conforming to the T1 (promulgated by American Telephone and Telegraph Company) interface to groups conforming to the NTT (promulgated by the Nippon Telephone and Telegraph Company) interface and vice versa. In addition to the differences in framing, the electrical representation of a data bit changes between T1 & NTT. This is referred to as the Transmission Line Code. T1 incorporates "Alternate Mark Inversion" (AMI) and NTT uses "Coded Mark Inversion" (CMI).
2. Description of the Prior Art
In a typical data communication network, series of data bits are exchanged which are partitioned into groups of frames, each frame comprising a plurality of multi-bit channels and one or more synchronization bits. However there are several ways in which data can be partitioned which are mutually incompatible. Therefore data cannot be exchanged between two systems using different interfaces without an interface converting device therebetween.